HTML Editor in FireFox works with limitations.
Other terms

HTMLEditor,FireFox, Text Style Firefox, Cut/Copy/Paste, Table modification HtmlEdit, Context Menu Html Editor
Reason and Prerequisites

HTML Editor works with the following limitations in Firefox
1) Cut Copy Paste don’t work by default. Please use the steps defined at http://www.mozilla.org/editor/midasdemo/securityprefs.html for using these features.
2) Applying of Text style removes the existing format from the text.
3) Table selection in the content area is not possible.
4) Table modification,doesn’t work.
5) In Firefox 2 context menu doesn’t work.
6) In Firefox no cursor is seen in the content area on setting focus when the content is empty. The text however can be added.
Solution

HTML Editor in FireFox works with above mentioned limitations.
HTMLB Editor is not supported for releases before NW04S(EP7.0)SP19 .
support for HTMLB Editor in firefox will be available in the following releases .
EP7.0 SP19 onwards
EP7.0 Ehp1 SP4 onwards
EP7.0 Ehp2 SP0 onwards
EP 7.1 SP9 onwards
EP7.1 Ehp1 SP3 onwards
EP7.1 Ehp2 Sp0 onwards